1
Marinating the Beef. In a bowl, combine the cumin, paprika, chilli powder, oregano, garlic and 2 tablespoons of oil. Add the beef and turn it until every piece is coated. For the best flavour, marinate the beef overnight. If you are short of time, give it at least 30 minutes before cooking.
2
Cooking the Beef in the Slow Cooker. In a heated pan, fry the beef alongside onions on high heat until they develop a nice colour. Transfer the beef and onions to a slow cooker. (Alternatively, you can use a pot or continue using the same pan.) Pour in enough stock to cover the meat and season with a teaspoon of salt. For a quicker cook time, set the slow cooker to high and let it cook for 3-4 hours. For overnight cooking, use larger beef pieces and set the cooker on a low setting.
3
Preparing the Sweet Peppers. In a separate pan, fry the sweet peppers on medium heat for about 10 minutes. Once done, set them aside.
4
Shredding and Mixing the Beef. Once the beef is tender, remove it from the slow cooker. Allow it to rest in its juices for a few minutes before taking it out. Shred the beef using your fingers. In a mixing bowl, combine the shredded beef, fried sweet peppers, chopped parsley, tomato paste, chipotle paste, and a portion of the meat cooking juices.
5
Making the Quesadilla. Warm the tortillas through first so they fold without cracking. Brush one side of a tortilla lightly with oil and lay it oiled-side-down on a hot frying pan. Scatter some of the cheese over one half, spoon the beef on top and finish with the rest of the cheese, so it melts on both faces and glues the fold shut. Keep the heat at medium. When the underside is golden, fold it over and press gently.
6
Serving Suggestions. Once cooked, remove the quesadilla from the pan and cut it in half. Serve hot and enhance the flavours with your favourite Mexican toppings like guacamole, roasted tomato salsa, sour cream, jalapenos, salad, and a dash of fresh lime juice.